Charge forming device for internal combustion engines



.Pune 16, 1936. 1 A. H. WElERTz ET A1. j 2,044,12

CHARGE FORMING DEVICE FOR INTERNAL COMBUSTIQN ENGINES Filed Marcin 2l, 1935 3 Sheets-Sheet 1 1935 5 sheets-sheet 2 June 16, 1936. A. H. WEIERTZ ET AL CHARGE FORMING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed March 2l,

@fill/[Lain m `lune 16, 1936. A. H. WEIERTZ ET A1. E 2,044,4l2

CHARGE FORMING DEVICE EOR NTERNAL COMBSTION ENGINES Filed March 21, 1955 5 Sheets-Sheet 15 Patented June 16, 1936 STATES PTENT OFFICE Axel Hugo Weiertz and Per Axel Renar Weiertz, Landskrona, Sweden Application March 21, 1935, Serial No. 12,268

In Sweden March 23, 1934 14 Claims.

This invention relates to charge forming devices for internal combustion engines". More particularly, the invention relates to such a device which may be used as an attachment to petrol engines to enable the use of a heavy hydrocarbon oil as a fuel in such engines. The device is of the type in which the heavy fuel is vaporized through heating in a vaporizer before it is admixed with the combustion air drawn in by the r engine. The heating is effected by the hot exhaust gases from the engine, and preferably a small quantity of the exhaust gases used for the heating is added to the fuel and used to assist.

in atomizing the liquid fuel to be vaporized as it l enters into the vaporizer. The supply of the liquid fuel to the vaporizer is controlled by means of a valve, and after vaporization the vaporized fuel freely enters into the suction intake pipe or manifold of the engine and is admixed therey in with the combustion air which enters into the said pipe or manifold through a valve controlled air inlet.

According to the invention the power of the engine is controlled according to the demands by i simultaneously controlling the said fuel and air valves which for this purpose are controllable by means of a common control mechanism. Further, according to the invention, the control valve in the air inlet is connected to a retarding I mechanism such as a dash pot or the like which is active for retarding the movement of the air valve in relation to the movement of the fuel valve when moving said valves in the direction for decreasing or shutting oif the fuel and air supplies to the vaporizer and to the intake pipe or manifold of the engine, respectively. This retardation of the movement of the air valve in relation to the movement of the fuel valve serves the purpose of creating a delay in the decrease of the air supply to correspond to the delay by which the quantity of vaporized fuel entering from the vaporizer into the intake pipe or manifold of the engines takes the Value corresponding to the decreased supply of liquid fuel to the vaporizor. In this manner the excess of fuel in relation to air in the charge otherwise occasionally turning up when decreasing or shutting olf the fuel and air supplies is avoided. Such an excess of fuel in relation to air in the charge drawn in by the engine is deleterious or'harmful due to the incomplete combustion and the objectionable smoke and odor in the burnt gases and the deposits in the engine cylinders resulting therefrom.

Further objects of the invention are to provide a device of the character set forth, which is of a simple, practical and efficient construction, as is hereinafter described with reference to the accompanying drawings illustrating two preferred embodiments of the invention.

In the drawings:-

Fig. l is a longitudinal section of one `of said embodiments of the charge forming device according to the invention.

Fig. 2 is a detail sectional View substantially 10 on the line II-II in Fig. l.

Fig. 3 is a longitudinal section of the other embodiment of the charge forming device according to the invention.

Fig. 4 is a side View, partially in section, of the l5 device according to Fig. 3.

Fig. 5 is a detail .sectional view substantially on the line V-V in Figs. 3 and 4.

Fig. 6 is a detail side view.

Fig. '7 is a detail sectional view. 20

Referring to Fig. 1 in the drawings, |00 is the intake pipe or manifold of the engine, and |02 is the exhaust pipe of the same. A mixing chamber for the vaporized heavy fuel oil and the air forming the charge to be drawn in by the engine, is made in the shape of a piece of tubing |04 and mounted in the intake manifold between the engine and an ordinary petrol carburettor |03, the vaporizer for Athe heavy oil being mounted within a chamber |05 which is connected in the ex- 30 haust pipe |02 and adapted to be passed by the exhaust gases. The tubular mixing chamber |04 is provided with an air inlet |06 adapted to be controlled and closed by means of a throttle valve |01. The chamber |05 interposed in the exhaust 35 pipe |02 is provided with two separate passages or channels |08 and |09 controlled by a switch valve ap H0. A vaporizing chamber in the shape of a tube extends through the exhaust gas passage |09 and opens into the mixing 40 chamber |04 preferably by means of a funnelshaped nozzle ||2 opening in the direction of now of the air through said chamber. The tube preferably is constructed with a cross sectional area which increases from the inlet end towards the outlet end of the tube, and preferably it is flattened in a gradually increasing degree in the direction from its outlet end towards its inlet end.

The inlet end of the vaporizing tube preferably is positioned in such a manner that it is closed by the switch valve flap ||0 when the latter is brought into a position completely closing the exhaust gas passage |09, and in this position of the said valve ap the whole amount of the exhaust gases is brought to pass the bypass channel |08.

Furthermore, the tube is mounted within the passage |09 in a manner that the exhaust gases sweep around the same when wholly or in part taking this way, and thereby a small portion of the said gases passes said tube and enters the mixing chamber |04, or the intake manifold of the engine, both due to the pressure existing within the exhaust pipe and due to the suction arising within the intake manifold.

A number of restricted admission inlets ||3 for the heavy fuel oil open into the tube not far from the inlet end of the same (compare Fig. 2), such cil inlets being at hand at the upper end of a small and preferably cylindrical and hollow member I4 inserted in an opening in the under side of the tube and positioned within the exhaust gas passage |09 so as to be swept by the exhaust gases passing the same, said hollow member preferably being provided with external ribs forincreasing its heat transmitting surface,

In the embodiment shown in Fig. 1, the hollow member ||4 is secured in a bore at the bottom of the chamber |05 by means of a sleeve-shaped screw |I5, and by means of an oil channel H0 the interior of the same is connected to an oil chamber ||I preferably made integral with the chamber |05 which is passed and heated by the exhaust gases. The oil chamber I|`l is provided with an oil supply pipe H8, and the oil level therein is adapted to be kept as constant as possible by a oat controlled valve means or, for instance, by means of an overflow pipe I |9.

The supply of the heavy fuel oil to the hollow member H4 from the oil chamber IH is adapted to be controlled by means of a needle valve |20. In a closed position of said needle valve it is adapted to be pressed against its seat by means of a spring |2|. One arm |22 of a bell crank lever extends into a recess in the valve stem and serves to lift the valve |20 from its seat, said bell crank lever being pivotally mounted on a shaft |23, and the other arm of the same being adjustably connected to an arm |24 pivotally mounted on the same shaft |23 and acted upon by a spring |25. The arm I 24 is further provided with an abutment |27 adjustably mounted around a pin |20 and resting against a roller, or the like, on an arm |28 fixed on a rotatable shaft |29 provided also with another fixed arm |30 which is connected to a control member in the shape of a pedal, or the like, by means of a suitable connection member I3 A bell crank lever |32 is pivotally mounted on the shaft |29, one arm of said lever being connected with the air throttle valve |0l by means of a suitable connection member, whereas the other arm of said lever is connected with a delaying or retarding mechanism in the shape of a dash-pot |34 provided with a springpressed piston, or the like.

Thearm |30 is provided with an abutment |35 adapted for coaction with the bell crank lever |32, and at rotation of the arm |00 for opening the valve |20 the said abutment rotates the bell crank lever |32 in a direction for opening the air throttle valve |01. At this rotation of the arm |30 the roller on'the arm |28 moves downwardly along the straight edge portion of the abutment |2'| so that the arm |24 is rotated in a direction to allow for lifting of the valve |20 by means of the spring |25. At rotationV of the -arm |30 in the opposite direction for closing thev Valve |20, the bell crank lever |32 is tilted back in a direction for closing the air throttle valve |01 under the action of the spring acting on the piston within the dash-pot, but the closing movement of the air throttle |01 is delayed or retarded by said dash-pot so that it is brought about with a certain amount of lag in relation to the closing of the fuel valve |20.

The ordinary petrol Carburettor |03 is used in starting the engine and in idle operation of the same, and under such conditions the air throttle A |01 is closed. When changing over to feeding 1o the engine with the heavy fuel oil, the Valve |20 and the air throttle |01 are opened, whereas the mixing throttle, or air passage, of the ordinary petrol Carburettor |03 is closed, so that this carburettor is set out of action, The chamber |05 l5 then has already been heated by the exhaust gases, of which at least a portion is conveyed though the passage |00 for heating the vaporizer for the heavy fuel oil. A small portion of the hot exhaust gases passes through the tube 20 iii and serves as an atomizing agent for the oil When entering the vaporizing tube through the restricted bores ||3. A rapid and complete vaporization of the heavy fuel oil is performed by the heat inherent in the portion of the exhaust 25 gasespassing the tube I|| and due to the heating of said tube by the exhaust gases sweeping around the same. The vaporization is effected without oxidation of the oil since the exhaust gases passing the vaporizing tube do not con- 3C tain any free oxygen, or in any case they are very poor in oxygen. Hence, in spite of the high temperature, no formation of coke and tar occurs within the vaporizing tube.

As the oil chamber ||1 is in heat transmitting 35 connection'withthe chamber |05 heated by the exhaust gases, a pre-heating of the heavy oil takes place already within said oil chamber. Before entering the vaporizing tube ||I, the oil is still further pre-heated within the hollow mem- 4( ber H4 swept by the exhaust gases. Together with the portion of the exhaust gases passing the tube iii, the vaporized heavy fuel cil from said tube enters the intake manifold of the engine, or the mixing chamber |04 connected thereto, and 4| is mixed with the air drawn in through the air inlet |00.

Between the mixing chamber |04 and the engine there is no throttle or the like at hand in the path of the inilowing fuel mixture, on which 5 the fuel can get a tendency to condense or accumulate in the shape of drops, but the fuel mixture has a free and unobstructed passage from the mixing chamber II4 to the engine cylinders, whereby the risk for a condensation of the vapor- 5 ized fuel on its way to the cylinders is prevented, or in` any case materially reduced. The high temperature attained by the vaporized fuel during its passage through the Vaporizer I I strongly heated by the exhaust gases does also assist herein in an essential degree.

During the running, the heating of the tube I may be controlled by adjustment of the switch flap valve ||0 whereby a greater or smaller portion of the exhaust gases may be by-passed through the passage |08. The reduced suction effect of the lower degree of vacuum occurring within the intake manifold of the engine at a greatly open position of the air throttle |01, when running at high loads, and acting on the por- 7 tion of the exhaust gases passing the tube will be automatically compensated for in a required degree by the higher pressure occurring in the exhaust pipe at high loads.

' When the supply of the heavy fuel oil is re- 7 ducedv or cut off by means of the valve |20, the air throttle |01 is closed with a sufficient delay for permitting a sucient admission of air for a complete combustion of such vaporized fuel which during some little space of time still might pass to the engine, so that a formation of soot and tar within the engine, and an exhaust of fumes through the exhaust pipe, will be avoided also under such circumstances.

Referring to the embodiment of the invention illustrated in Figs. 3 7, I represents a housing provided at both ends with flanges 2 by which the housing is adapted to be connected in the exhaust pipe of the engine so that the exhaust gases pass through the housing I. In one side the housing I has an opening closed by means of a cover il secured by means of bolts 3. In the housing I there is provided a vertical partition 5, and at the upper edge thereof on a shaft 'I there is journaled a switch flap valve 5. By adjustment of this valve the exhaust gases or a controllable portion thereof may be caused to pass n one side or the other of the partition 6. On the inside of the cover 4 there is secured by means of bolts-9' a hollow body 9 forming a bent channel I5 beginning in the upper side of the body 9 and ending in the side thereof facing the cover 4. The body 9 is so disposed that it is swept by the exhaust gases passing between the cover 4 and the partition 6 in the housing I and is highly heated thereby. For increasing the heat transmitting surface of the body 9 it may be provided with ribs I I. In the cover d there is provided an opening I2 in registe with the opening of the channel IG in the adjacent side of the body S. On the outside of the cover i there is secured by means of bolts I3 a housing Ill having an inlet Mai communicating with the channel Ii! in the body 9 through the opening I2 in the cover Il. On its under side the housing Irl is provided with an air inlet socket Ilib in which there is provided a rotatable shaft I5 carrying a throttle valve I5. On its upper side above the air inlet socket |52) the housing I i is provided with a bent outlet socket Ilic adapt-ed to be connected to the intake pipe er manifold I1 of the engine. The connection between the intake pipe I 1 and the socket Mc preferably is constructed as shown in Fig. 3 and consists of a branch socket I I8 connected between the intake pipe I1 and an ordinary petrol Carburettor IS having the usual throttle valve 25, the branch 2l on the socket I8 being connected to the socket Hic by means of a tube 22 and ordinary pipe-couplings 23.

On the outside of the cover il there is also secured by means of screws 25 a fuel vaive housing 25. In its lower portion this valve housing 25 is provided with a transverse channel 25, and to one end thereof there is connected a tubular nipple 21 secured by means of a bolt 2S extending through the nipple and the channel 26 and provided with nuts 29 at both ends, which at the same time serve the purpose of closing the opposite ends of the nipple 21 and the channel 25,

, respectively. The nipple 21, preferably in its under side, is provided with a connection socket for a fuel supply conduit SI through which the liquid fuel is supplied from, for instance, a vacuum tank disposed at a suitable level above the charge forming device, so that the fuel is supplied under a moderate and substantially constant pressure. If a pump is used for delivering the fuel a pressure relief valve may be provided in the fuel supply conduit. On the nipple 2i t there may be provided an. air chamber 32 cornmunicating with the interior of the nipple. In the valve housing 25 there is provided a passage 33 extending from the channel 25 and formed by a valve seat 34 secured in the lower end of a sleeve 35 fitted in a vertical bore in the housing 25 and secured by means of a nut 36 which at the same time serves as a guide for a needle valve 31 coacting with the valve seat 3i for controlling the fuel supply. In the housing 25 there is provided a channel 38 extending from an opening in thev side of the sleeve 35 and having a continuation in the form of a bore Si! through the cover II and a bifurcated channel l5 in the.

body 9. The two branches of the bifurcated channel 4U open into an annular nozzle slot 5I (see also Fig. 7) formed around the lower end of a valve seat 42 secured in the upper end of the.

channel IB. In the valve housing 25 there is also provided an air inlet 43 which o-pens into the sleeve 35 through an opening in the side thereof. f

The air inlet B3 is adjustable by means of an adjusting screw 44 and can be put in communication with the fuel passage in the housing 25 through a recess A5 in the stem of the needle valve 31 and a recess 45Y in the inside of the sieeve 35 when the needle valve is moved downwardly, that is towards closing position. Coacting with the valve seat 42 is a valve 41 havinga cylindrical extension 41a leaving between it and the valve seat a narrow annular passage 48 opening adjacent to and immediately inside of the opening of the fuel nozzle slot 4I. The valve il is suspended by means of a stem i9 guided in a vertical bore in the cover 4 and engaged with an arm 55 secured to a shaft 5I journaled in ears 52 on the outside of the cover Il. On the inner wall of the channel IIJ just below the valve seat 42 there is provided a helical rib or thread 53 of a large pitch.

Secured to the upper side of the housing 25 by means of screws 54 is a bracket 55. Journaled in this bracket is a horizontal shaft 55 which outside of the bracket carries an arm 51 fixed to the shaft and an arm 58 which is rotatable on the shaft. On the hub of the arm 58 there is secured an arm 59. The arm 51 is adapted to be operatively connected to a pedal or the like by means of a rod and carries an adjustable abutment screw 6I for actuation of the arm 58 to which the throttle valve I6 is operatively connected by means of an arm 52 on the shaft 5I and a link 53 connecting the arm 62 to the arm 59 secured on the hub of the arm 58. The arm 51 is also provided on a projection 51a with an abutment screw Ell or the like for actuation of an arm 55 (preferably provided with a roller 65) secured o-n the shaft 5I. The arm 56 is actuated by a spring 61 biasing the arm towards fully open position of the valve 41. Secured to the inner end of the shaft 55 is an excenter or cam 58 (Figs. 5 and 6), and journaled on a shaft 69 on the bracket 55 is an arm 1G having its free end engaged in a notch in the stem-0f the fuel needle valve 31 and being provided with an adjustable screw 1i with which it rests on the excenter or cam 68. The needle valve 31 is actuated by a spring 12 tending to move the needle valve downwardly. Over the needle valve 31 and the control mechanism therefore now described there is provided a cover 55a. secured to the housing 25 by means of screws 55h. Pivoted tothe arm 58 by means of a bolt 13 is the piston rod 14 of a piston 'i5 movable within a cylinder 16 which at its lowei` end is pivotally connected to the housing Ill by means of a bolt 11. Preferably integral with the cylinder 16. isL a-chamber 18- communicating with the cylinder at its upper end through an opening 19 and at its lower end through an opening 8| provided with a check valve in the form of a ball B or the like. Further there is provided a number of communicating openings 82 and 83 between the cylinder 15 and the chamber 18, said openings being adjustable by means of adjusting screws 84 and 85. The cylinder 16 and the chamber 18 are adapted to contain a quantity of liquid such as oil or glycerin and form togcther with the piston 15 a dash-pot mechanism active for retarding the movement of the piston 15 in the downward direction.

The operation of the embodiment of the heavy fuel charge forming device according to the invention described with referencey to Figs. 3-'1 may be declared as follows. In the said figures the parts of the said device are shown in the positions occupied when the device is set for running the engine under full load, the throttle 20 of the petrol Carburettor being closed so that the engine is fed only with heavy fuel. The exhaust gases from the engine pass through the housing I and highly heat the body 9 forming the vaporizer for the heavy fuel, and a small proportion of the hot exhaust gases pass through the open valve 41 and the narrow annular passage 48 to the channel I0 and ,assist in atomizing the liquid fuel entering the channel I8 throughV the nozzle slot 4I. The gases and fuel entering and passing through the channel II] are set in a rotary or turbulent motion by means of the helical rib or thread 53, and through this rotation or turbulence the fuel particles are thrown against the hot walls of the channel Ill, whereby quick and complete vaporization of the fuel is obtained without formation of deposits. In the housing I4 and the socket I4c the fuel vapors co-mingle with the combustion air drawn in through the air inlet socket I4b, and the mixture or charge thus formed flows into the intake pipe or manifold I1 of the engine. The heating effect of thel exhaust gases upon the vaporizer 9 can be varied or controlled by means of the switch valve 8, the shaft 1 of which for this purpose being provided with an arm 85 operable by means of a Bowden cable 81 or the like.

In order to decrease the engine power the arm 51 and thereby the shaft 56 is rotated in counterclockwise direction as seen in Fig. 4. Hereby the fuel needle valve 31 is allowed to be moved downwardly by the spring 121 for decreasing the fuel supply, and at the same time the recess 45 in the stem of the needle valve 3'! is put in communication with the recess 46 in the sleeve 35, so that when running the engine under moderate and low loads a small amount of air is drawn in and mixed with the fuel in the valve housing 25. At the said rotation of the arm 51 also the arm 58 and thereby also the arm 59 and the air throttle valve I6 are allowed to rotate, for instance under the action of a spring 88 (Fig. 4) on the shaft of the throttle valve, whereby the latter is moved towards closed position. This movement of the throttle valve I5 for decreasing the air supply to correspond to the decreased fuel supply is retarded, however, through the dash-pot mechanism connected to the arm 58. This retardation of the closing movement of the air throttle I6 in relation to the closing movement of the fuel supply valve 31 serves the purpose of preventing an occasional excess of vaporized fuel in relation to the air in the charge drawn in by the engine. Through the provision of the two throttle openings 82 and 83 in the dash-pot mechanism the retarding effect of this mechanism upon the closing movement of the air throttle valve I6 will beA greater towards the end of said movement. The lower end of the piston 15 is provided with a recess 15a sothat the position in which the greater retardation effect upon the closing movement of the air throttle valve I6 sets in can be altered by' turning the piston half a revolution around its axis. The engine can be run idly on the volatile fuel or on the heavy fuel, as the case may be. In the latter case the idle running position of the charge forming device can be predetermined by means of an arm 98 pivoted to the bracket 55 by means of a screw 89 or the like and carrying an abutment 9| for the arm 51, the said arm 90 being operable for bringing the said abutment in the path of the arm 51 by means of a Bowden cable 92 or the like. Thus, it is necessary to use the ordinary petrol Carburettor I9 only for starting the engine when cold. If the engine is restarted while still hot, it is possible to start directly on the heavy fuel. When completely shutting oif the supply of the heavy fuel the abutment screw 64 on the arm 51 strikes the roller 65 on the arm 66 and rotates the latter against the action of the spring 61, so that the valve 41 is closed. For the arm 66 there is provided outside on the cover 4 an insulated stop screw 94 at the same time serving as a contact with which the arm 66 in the open position of the valve 41 makes contact for closing an electric signal circuit con- 9 taining, for instance, a signal lamp. This lamp is glowing whenever the heavy fuel charge forming device is in operation.

Through the provision of the air chamber 32 in communication with the fuel supply conduit is obtained that, when the fuel valve 31 is lifted suddenly, the fuel flow through the valve is also suddenly increased without a sudden acceleration of the fuel in the whole fuel supply conduit.

When using a vacuum tank the evacuation thereof preferably is effected by means of an ejector disposed in the air inlet socket I4b, which consists of a cone 95 having an annular channel 96 and suction openings 91 to this channel 96 from the inside of the cone. 'I'he vacuum tank (not shown) is connected to the annular channel 96 by means of a conduit 98. The upper end of the cone 95 projects into the housing I4 and is provided with holes 99 for draining off any liquid fuel oil leaking through the fuel valve when the device is out of operation.

The charge forming device as described herein makes it possible to feed an ordinary petrol engine with a heavy fuel oil while obtaining complete and smokeless combustion under all conditions of operation. Further, the device is of a relatively simple construction and can be mounted without diculty in most existing engines, especially automobile engines. Further the device,v especially in the embodiment thereof illustrated in Figs. 3-7, is easy to put together and dismount for inspection and repair. For suiting the device to different engines it is only the housing I and the branch socket I8 which perhaps must be constructed somewhat differently according to special circumstances, while all other parts may be the same. Further the construction is such that the bracket 55 and the parts carried thereby can be mounted on either side of the device. The same is true as regards the nipple 21 and several other parts, and this is of some importance because of the` fact that in many cases but a very restricted space is available for building in the device.

Of course the detail construction of the device can be varied Within reasonable limits without departing from the spirit of the invention.

What we claim and desire to secure by Letters Patent is:

1. A charge forming device for internal combustion engines, comprising in combination, a housing adapted to be connected to the exhaust pipe of the engine and to be passed by the exhaust gases, a vaporizer housed in said housing and adapted to be swept by the exhaust gases so as to be heated thereby, means for supplying liquid fuel to said vaporizer, including a valve means for controlling the fuel supply to the vaporizer, a socket adapted to be connected to the suction intake pipe of the engine and provided with an air inlet, the vaporizer being adapted to discharge the vaporized fuel into said socket for mixing the vaporized fuel with the air drawn in by the engine through said air inlet, a valve means for controlling said air inlet, means for simultaneously controlling said fuel valve means and said air valve means for the purpose of controlling the power of the engine, and a retarding means for retarding movement of said air valve in relation to movement of said fuel valve when moving said valves in a direction for decreasing the fuel supply to the vaporizer and the air supply to the intake pipe of the engine, respectively.

2. A charge forming device for internal combustion engines as claimed in claim l, in which the vaporizer has an inlet to permit a small amount of the exhaust gases to enter the vaporizer to assist in atomizing the liquid fuel as it enters the vaporizer.

3. A charge forming device for internal combustion engines as claimed in claim 1, in which the vaporizer is in the form of a tube having a restricted inlet end for exhaust gases and a wider discharge end opening into the socket having the air inlet, and in which inlets for the liquid fuel into the vaporizer tube are provided in the form of narrow bores in the upper end of a hollow body projecting through an opening in the under side of the vaporizer tube near the said inlet end thereof.

4. A charge forming device for internal combustion engines as claimed in claim 1, in which the housing adapted to be connected to the exhaust pipe of the engine besides of an exhaust gas passage containing the vaporizer is provided with a passage for by-passing the exhaust gases or a. controllable portion thereof in relation to said first-mentioned passage.

5. A charge forming device for internal combustion engines, comprising in combination, a housing adapted to be connected to the exhaust pipe of the engine and to be passed by the exhaust gases and provided with a side opening, a cover for said opening, a vaporizei` in the form of a hollow body secured on the inside of said cover and adapted to be swept by the exhaust gases passing said housing so as to be heated thereby, means for supplying liquid fuel to said vaporizer, including a. valve means for controlling the fuel supply to said vaporizer, said cover having an opening, a housing secured on the outside of said cover and forming a mixing chamber communicating with said vaporizer through said opening in said cover and having an air inlet and a mixture outlet adapted to be connected to the intake suction pipe of the engine, a valve means for controlling said air inlet, means for simultaneously controlling said fuel valve means and said air valve means for the purpose of controlling the power of the engine, and a retarding means for retarding movement of said air valve in relation to movement of said fuel valve when moving said valves in a direction for decreasing the fuel supply to the vaporizer and the air supply to the mixing chamber, respectively.

6. A charge forming device for internal combustion engines as claimed in claim 5, in which the said hollow body forms a vaporizing chamber in the shape of a bent channel extending from the upper side of said body to the side thereof facing the said cover.

7. A charge forming device for internal combustion engines as claimed in claim 5, in which the air inlet to the mixing chamber is in the form of an inlet socket on the under side of the housing forming the mixing chamber, the air control valve being provided in the form of a throttle valve in said inlet socket; and in which the mixture outlet from the mixing chamber is in the form of a bent outlet socket on the upper side of said housing above the said air inlet socket.

8. A charge forming device for internal combustion engines as claimed in claim 5, in which the fuel control valve is provided in a valve housing secured on the outside of the said cover and connected by means of fuel channels in the cover and the vaporizer body to a vaporizing chamber formed by said body and having the shape of a bent channel extending from the upper side of said vaporizer body to the side thereof facing the said cover, a valve controlled inlet for exhaust gases to said bent channel being provided in the upper end thereof.

9. A charge forming device for internal combustion engines as claimed in claim 5, in which the vaporizer body forms a vaporizing chamber in the shape of a bent channel extending from the upper side of said body to the side thereof facing the said cover; and in which a fuel inlet to said bent channel is in the form of an annular nozzle slot formed between the inside of said hollow body and a valve seat secured in the upper end of the said bent channel in the said body, a valve coacting with said valve seat and adapted to admit a small amount of exhaust gases to the vaporizing chamber being provided with a cylindrical extension forming with the said Valve seat a narrow annular passage opening adjacent to and immediately inside of the said annular nozzle slot.

10. A charge forming device for internal combustion engines as claimed in claim 5, in which said fuel control valve is located in a valve housing secured on the outside of said cover, and in which a bracket secured on said fuel valve housing carries a rotatable shaft provided with a cam for lifting the fuel valve and with a fixed arm adapted to be operatively connected to a pedal or the like, said shaft also carrying a loose arm adapted to be actuated by an abutment on the rst-mentioned arm and connected with the air control valve in the air inlet to the mixing chamber and also with a dash-pot mechanism which is active for retarding closing movement of the air control valve in relation to closing movement of the fuel control valve.

11. A charge forming device for internal combustion engines as claimed in claim 5, in which said retarding means consist of a dash-pot mechanism so constructed as to have a greater retarding effect on the closing movement of the air control valve towards the end of this movement than at the beginning thereof.

12. A charge forming device for internal combustion engines as claimed in claim 5, in which the means for supplying liquid fuel to the vaporizer includes a valve housing for the fuel control valve and a fuel supply conduit connected to said valve housing by the intermediary of a nipple provided with an air chamber communicating with the fuel duct in the nipple.

13. A charge forming device for internal combustion engines as claimed in claim 5, in which Vthe fuel control valve consists of a needle Valve mounted in a valve housing provided With an air inlet controlled by the stem of said needle valve, for admixing a small amount of air with the fuel on its way to the vaporizer When running the engine at low and moderate loads.

14. A charge forming device for internal combustion engines as claimed in claim 5, in which the vaporizer body forms a vaporizing chamber in the shape of a bent channel extending from the upper side of said body to the side thereof facing said cover, and in which a fuel nozzle and a valve controlled inlet passage for exhaust gases open into the upper end of said channel, a helical rib of large pitch being provided on the wall of said channel below said fuel inlet nozzle and valve 1 controlled exhaust gas inlet passage.

AXEL HUGO WEIERTZ. PER AXEL REINAR WEIERTZ. 

